A single control unit has been disposed in a single place within a building (e.g., a building occupied by companies or tenants) where a large number of air conditioning facilities is installed, and the air conditioning facilities are controlled by the control unit (see Japan Laid-open Patent Application Publication No. JP-A-H09-196444). Further, the control unit is configured to obtain operational data from the air conditioning facilities installed in the building and assess operational conditions of the air conditioning facilities for effectively managing the air conditioning facilities.